Prostacyclin, an organic compound related to prostaglandins, is (5Z)-9-deoxy-6,9.alpha.-epoxy-.DELTA..sup.5 -PGF.sub.1.alpha. and is represented by the formula ##STR2## For its synthesis and structure see for example R. A. Johnson et al., J. Am. Chem. Soc. 99, 4182 (1977) and Prostaglandins 12, 915 (1976), and E. J. Corey et al, cited, J. Am. Chem. Soc. 99, 20006 (1977). For some of its biological properties and uses see the references cited in the Johnson references. Prostacyclin is referred to as "PGI.sub.2 ", see Anonymous, Prostaglandins 13, 375 (1977).
Prostacyclin and prostacyclin-type compounds, including derivatives and analogs, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. A few of those biological responses are: inhibition of blood platelet aggregation, stimulation of smooth muscle, inhibition of gastric secretion and reduction of undesirable gastrointestinal effects from systemic administration of prostaglandin synthetase inhibitors.
Because of these biological responses, prostacyclin and prostacyclin-type compounds are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
Prostacyclin and prostacyclin-type compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent postoperative surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. Other in vivo applications include geriatric patients to prevent cerebral ischemic attacks and long term prophylaxis following myocardial infarcts and strokes.
Prostacyclin and prostacyclin-type compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents; they are also useful in reducing the undesirable gastrointestinal effects resulting from systemic administration of anti-inflammatory prostaglandin synthetase inhibitors. In addition, prostacyclin or prostacyclin-type compounds are useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A and histamine which are released from cells activated by an antigen-antibody complex.
Prostacyclin or prostacyclin-type compounds are also useful in treating peripheral vascular disease in humans. The term peripheral vascular disease as used herein means disease of any of the blood vessels outside of the heart and to disease of the lymph vessels.
A complete description of the various uses of prostacyclin or prostacyclin-type compounds is set out in U.S. Pat. No. 4,124,599.